What happens to liquids as they are heated and cooled?
Materials needed
- · Narrow-necked jar with a one whole rubber stopper.
- Balloon stick (available from craft or party supply stores)
- · Marker, rubber band, or masking tape
- · Water
Procedure
1. Fill the jar completely with cold water.
2. Insert the plastic tubing through the rubber stopper.
3. Place the stopper in the jar. As you press the stopper into place, three should be no air space beneath the stopper, and water should be force part way (not more than half way) up the tube above the stopper.
4. Mark the tube at the water level with a marker, or by a putting a rubber band or tape around it.
5. Place the jar in a window in direct sunlight.
6. Check the water level in the tube every few minutes for at least two hours.
7. What happened to the water level as the water warmed in the sunlight?
8. Remove the jar from the sunlight and place it in a cool place.
9. Again check the water level in the tube every few minutes.
10. What happened to the water level as the water cooled?
11. What can you say about the effect of temperature change on liquids?
2. Insert the plastic tubing through the rubber stopper.
3. Place the stopper in the jar. As you press the stopper into place, three should be no air space beneath the stopper, and water should be force part way (not more than half way) up the tube above the stopper.
4. Mark the tube at the water level with a marker, or by a putting a rubber band or tape around it.
5. Place the jar in a window in direct sunlight.
6. Check the water level in the tube every few minutes for at least two hours.
7. What happened to the water level as the water warmed in the sunlight?
8. Remove the jar from the sunlight and place it in a cool place.
9. Again check the water level in the tube every few minutes.
10. What happened to the water level as the water cooled?
11. What can you say about the effect of temperature change on liquids?
For problems solvers:
if a motorist goes to the filling station on a hot day and fills the fuel tank clear to the brim, then sparks the vehicle in the sun for two or three hours, sometimes tank will overflow and spill fuel onto the ground. Think about the above activity and see if you can explain why the tank overflows. The manager at your local filling station would probably be glad to discuss to it with you if you have any questions or if you‘d just like to find out if your explanation is correct. Any experienced truck driver could also discuss it with you.
Teacher information
The ideal tube for this activity is a balloon stick, available at party supply outlets.
As the jar of water warms in the sunlight, the water will expand and the water level will expand and the water level will rise in the tube, demonstrating that as the temperature of liquid increases the liquid expands.
As the water cools it will contract, and the level of the water in the tube will drop.
If food coloring is available, have students add a few drops to the drops to the water. This makes the water level in the tube easier to see, and the change is more evident.
This device can become a thermometer if you have students attach a card to the tube and mark the card at different temperatures, by taking temperature readings from a commercial thermometer. Water evaporation in the tube will eventually destroy the accuracy of it as a thermometer and it will need to be re calibrated.
Filling stations store gasoline in large tanks beneath the ground. Thus, the fuel is cool. if a motorist fills the tank, then parks the vehicle in the sun for a time, the fuel will expand from the heat and will sometimes overflow onto the ground.
As the jar of water warms in the sunlight, the water will expand and the water level will expand and the water level will rise in the tube, demonstrating that as the temperature of liquid increases the liquid expands.
As the water cools it will contract, and the level of the water in the tube will drop.
If food coloring is available, have students add a few drops to the drops to the water. This makes the water level in the tube easier to see, and the change is more evident.
This device can become a thermometer if you have students attach a card to the tube and mark the card at different temperatures, by taking temperature readings from a commercial thermometer. Water evaporation in the tube will eventually destroy the accuracy of it as a thermometer and it will need to be re calibrated.
Filling stations store gasoline in large tanks beneath the ground. Thus, the fuel is cool. if a motorist fills the tank, then parks the vehicle in the sun for a time, the fuel will expand from the heat and will sometimes overflow onto the ground.
No comments:
Post a Comment